This invention relates to the method of water spreading to the evaporative pads in fixed or moveable evaporative coolers.
One form of evaporative air cooler consists of a cabinet having four or more sides at least one of which contains an absorptive pad in which is contained a fibrous absorption material, a water sump, a pump, a water distribution system for wetting the absorption pad, and a fan and motor assembly for drawing air through the wetted absorbent material contained in the pad. The successful operation of such an evaporative cooler relies on water being distributed to the absorptive pads in sufficient quantities and in a consistently uniform manner along the pads. The cooler must have all parts of the absorptive pads constantly wet to perform satisfactorily.
One of the practical difficulties encountered in this type of cooler is the uniformity of water distribution, and the tendency of water distribution systems to clog with foreign material.
The method of water distribution varies considerably. One such existing system pumps the water to a conduit under the cabinet lid with a plurality of holes. which in turn distribute the water into a second distributor, generally in the form of a trough, at the top of the filter pad frame. The holes in the distributor are relatively small and are frequently blocked. Uniformity of water distribution is poor due to the small holes required and variations in flow to the holes from out of level installation.
In other systems the pump is connected via a conduit or conduits to a water distributor or distributors, which distribute water to a spreader bar or bars with a plurality of open channels, mounted close to the underside of the cooler lid. Such a system is described in Australian Patent No. 56612/80. These systems are less prone to blockages and can tolerate a much greater degree of out of level installation before the uniformity of water distribution is affected. However, since the distribution system is under the lid, blockages are not easily seen and cleaning generally requires dismantling of the system.
It is well known that in the event of blockage of the apertures in the water distribution conduit, or the channels of a spreader bar, the efficiency of the air conditioner is severely impaired. One of the main practical difficulties encountered with this type of air conditioner has been attributed to the non uniform distribution of water through the fibrous absorbent material of the pad. Excessive water in parts of the pad can result in water pulling off the filter pads and entering the fan. A deficiency of water in another part of the pad will result in reduced water evaporation and the entry of hot air directly into the cooler thereby diluting air that has been fully cooled by the pads and reducing the cooling capacity of the cooler.
The object of the present invention is to provide an improved water distribution system which ameliorates the restrictions and deficiencies of the currently available systems.
This present invention provides a water spreader arrangement for use in an evaporative cooler, said spreader including an inlet leading to a plurality of generally vertical projections disposed over a plurality of levels, said projections being adapted to divide a single stream of water entering said inlet into a plurality of outlet streams having a predetermined ratio of flow rates therebetween and wherein said outlet streams can be fed to an evaporative pad of the evaporative cooler.
In a preferred form, the outlet streams have substantially the same flow rate. Preferably, a cooler incorporating the present invention includes a plurality of spreaders around the upper periphery of the evaporative pads.